Speed control mechanism for strand winding apparatus

ABSTRACT

A mechanism for selectively controlling the speed of a precision yarn winder or other strand winding apparatus so as to alternatively realize during a winding operation either constant yarn speed or constant takeup spindle speed, or constant spindle speed during any desired initial part of the operation and constant yarn speed during the remainder thereof. The mechanism also permits automatic termination of the winding operation when desired. The mechanism includes a drive-motor control circuit having a first subcircuit and second subcircuit alternately connectable with the variable speed drive motor of the winding apparatus. The first subcircuit includes a variable resistor and another resistor arranged in parallel relationship. During a winding operation, a mechanical linkage increases the resistance of the variable resistor in response to the increasing diameter of the strand package being formed upon the takeup spindle. When the first subcircuit is connected to the drive motor, the resulting increase in its effective resistance decreases the speed of the drive motor and therefore of the takeup spindle hyperbolically in relation to the increasing package diameter, so that constant strand speed is maintained. The second subcircuit is employed, either throughout a winding operation or during only an initial part thereof, when constant speed of the takeup spindle is desired.

United States ates [m seesaw [72] Inventors RichardLSavageau Seneca; Richard R. Pierce, Easley, both oi, S.C. [2|] Appl. No. 866,779 [22] Filed Oct. I5, 1969 [45] Patented Aug. 10, I971 [73] Assignee Maremont Corporation Chicago, Ill.

[54] SPEED CONTROL MECHANISM FOR STRAND WINDING APPARATUS 1 Claim, 4 Drawing Figs.

[52] US. Cl 242/45 [5 l] Int. Cl 365i: 59/38 [50] Field otSearch.. 242/45,

[56] References Cited UNITED STATES PATENTS 2,296,959 9/ l 942 Swanson 242/45 2,3 i 7,290 4/ l 943 Mcllvried 242/45 2,355,634 8/l944 242/45 2,594,427 4/ l 952 242/45 3,048,343 8/ l 962 242/45 3,180,584 4/1965 Blunck et al 242/45 Primary Examiner-Stanley N. Gilreath Auomey-Donald H. Feldman AESTRAtIT: A mechanism for selectively controlling the speed of a precision yarn winder or other strand winding apparatus so as to alternatively realize during a winding operation either constant yarn speed or constant takeup spindle speed, or constant spindle speed during any desired initial part of the operation and constant yarn speed during the remainder thereofv The mechanism also permits automatic termination of the winding operation when desired. The mechanism includes a drive-motor control circuit having a first subcircuit and second subcircuit alternately connectable with the variable speed drive motor of the winding apparatus. The first subcircuit includes a variable resistor and another resistor arrangedin parallel relationship. During a winding operation, a mechanical linkage increases the resistance of the variable resistor in response to the increasing diameter of the strand package being formed upon the takeup spindle. When the first subcircuit is connected to the drive motor, the resulting increase in its effective resistance decreases the speed of the drive motor and therefore of the takeup spindle hyperbolically in relation to the increasing package diameter, so that constant strand speed is maintained. The second subcircuit is employed, either throughout a winding operation or during only an initial part thereof, when constant speed of the takeup spindle is desired.

PATENTED AUG] man 3, 598,329

sum 1 OF 3 INVENTORS RICHARD J. SAVAGEAU RICHARD R.PIERCE MXQMM THEIR AGENT SHEET 2 HF 3 PAIENTEUAuc I 0 m:

INVENTORS RICHARD J. SAVAGEAU RICHARD R. PIERCE BY bawdy 74 Z/MW/ THEIR AGENT .PATENIEBwswen 3,598,329

' sum: 0F 3 v (a 56 CAPACITOR ME2 TO MOTOR SGCAPACITOR 48 He CONTROLLER IN ENTORS RICHARD J. SAVAGEAU RICHARD R. PIERCE BY mxz ww THEIR AGENT SPEED CONTROLMECI-IANISM FOR STRAND WINDING APPARATUS BACKGROUND OF THE INVENTION This invention relates to speed control mechanisms for precision yarn winders or other strand winding apparatus wherein a strand package of increasing diameter is formed upon a takeup spindle assembly as a winding operation progresses.

When a constant speed of the takeup spindle of such apparatus is maintained during a winding operation, the strand speed tends to increase linearly with the increasing diameter of the strand package being formed. This is in accordance with the formula s=4rdw, where s is the yarn speed, at is the package diameter and w is the rotational frequency or speed of the spindle in revolutions per minute. In many operations involving the winding of textile strands in particular, an increase in the strand speed is highly objectionable. For example, if the incoming strand is being treated in some way, as by passage through a'treatment bath and/or drying oven, the treatment accorded successive lengths of the strand will not be uniform if its speed varies. Additionally, there usually exists a maximum strand speed, dictated by the nature of the strand supply source and/or other factors, which must not be exceeded during any particular winding operation. Even if a winding apparatus maintains a constant spindle speed adapted to exactly realize the maximum permissible strand speed at the precise instant of termination of the winding operation, the apparatus is obviously not operating at its peak efficiency during the majority of the operation.-

Objectionable variations in strand tension also frequently accompany actual or attempted variations in strand speed. Elimination of such tension variations by the use of tensioncontrol devices is expensive and at times ineffectual, particularly when the strand speed tends to vary greatly during the winding operation.

SUMMARY OF THE INVENTION The present invention provides a highly reliable but relatively inexpensive mechanism for selectively controlling the speed of a winding apparatus of the type described so as to permit the realization, throughout a winding operation if desired, of a constant strand speed, Le, a strand speed varying no more than approximately plus or minus five per cent from a desired norm. In a preferred embodiment, the mechanism also alternatively permits the realization of constant takeup spindle speed throughout the winding operation, or constant spindle speed during any desired initial part of the operation and constant yarn speed during the remainder thereof, together with automatic termination of the winding operation at any desired point.

In accordance with the formula s=1rdw, previously set forth herein, the spindle speed w is an inverse function of the diameter d of the strand package formed during a winding operation, and therefore must be varied hypcrbolically as the diameter d of the strand package increases if a constant yarn speed .r is to be maintained. The mechanism according to the present invention so varies the speed of the takeup spindle by the provision, in association with the spindle drive means, of a control circuit having a pair of resistors-the resistance of at least one of which is changed as the strand winding operation progresses and the package diameter increases-arranged in parallel. Due to the parallel arrangement of the resistors, the voltage drop across the control circuit is inversely proportional to the changes in resistance of the variable resistor, and the spindle speed therefore also varies inversely with the changes in resistance. When plotted upon a graph in which one axis represents resistance and the other ,axis represents diameter, the spindle speed therefore defines a hyperbolic curve.

In a preferred embodiment of the control mechanism, the aforesaid parallel resistors are included within a first subcircuit of the control circuit, which further includes a second subcircuit alternately connectable by transfer switch means to the spindle drive means for when desired causing operation of the spindle at any predetermined constant speed. By actuation of the transfer switch at the appropriate point during a winding operation, the spindle may be operated at its maximum speed during the initial part of such operation and until the strand speed reaches its maximum permissible value, and thereafter operated at decreasing speeds maintaining the strand speed at its maximum permissible value until the winding operation has been completed. When the nature of the particular strand and other attendant circumstances permit the winding operation to be conducted in this manner, the full operating capability of the winding apparatus is realized.

The control mechanism is particularly, but not exclusively, adapted for utilization in association with a precision yarn winder of the type having a variable speed motor drivably connected to a takeup spindle assembly mountedfor movement away from a yarn traversing assembly, as the diameter of the yarn package increases during a winding operation, by asupport arm mounting the takeup assembly at one end thereof and having its other end secured to a pivotable drum. Movement of the drum during a winding operation is employed to vary, in accordance with the increasing package diameter, the resistance of the control circuits aforesaid variable resistor, and therefore varies the overall resistance of that first subcircuit which is connectable to the drive motor when constant yarnspeed is desired. Movement of the drum of the winding apparatus is also employed for actuating, at any desired time during the winding operation, a transfer switch for alternately connecting the two suhcircuits to the drive motor, and a fullpackage switch for stopping the winding operation.

Various features and advantages of the invention will be apparent from the following description of an illustrative embodiment thereof, which should be read in conjunction with the accompanying drawings, in which:

FIG. I is a front perspective view of a strand winding apparatus equipped with a control mechanism embodying the invention;

FIG. 2 is an enlarged rear elevation, partially broken away to disclose details of construction of the control mechanism, of that upper portion of the apparatus indicated by the arrows 2-2 of FIG. 1;

FIG. 3 is a vertical section taken substantially along line 3-3 of FIG. 2; and

FIG. 4 is a schematic representation of the control circuit of the mechanism.

The strand winding apparatus identified in its entirety in FIG. 1 by the numeral 10 comprises a well-known type of precision yarn winder including a frame 12 having a lower base I4 and upper housing 30; a takeup spindle assembly 20 upon which yarn Y, conducted from a suitable supply source [6 and through various guiding, treating and/or tensioning devices 18, is adapted to be formed into a tapered or cylindrical package 22 of progressively increasing diameter during a winding operation; a yarn traversing assembly 24 extending from housing 30 and including a freely rotatable ball 26 extending generally parallel to takeup spindle assembly 20 and engageable during a winding operation with the periphery of the package 22 being formed; means including a support arm 28 mounting spindle assembly 20 at its upper end for movement of the spindle assembly away from assembly 24 and bail 26 as the diameter of package 22 increases, the lower end of arm 28 being secured to a drum 32 (FIG. 3) projecting through front wall 29 of housing 30 and mounted by bearing 34 for pivotal movement about its axis; and variable speed drive means including a variable speed electric motor M drivably connected by timing belts and other conventional linkages (not shown, but extending in part through drum 32 and arm 28) to spindle assembly 20 and the yarn traversing mechanism of assembly 24. Although the control mechanism of the invention is particularly adapted for utilization in as sociation with an apparatus of the type shown in FIG. 1, its use is not restricted thereto since principles of the invention are equally applicable to strand winding apparatus of other types.

FIG. 4 schematically shows the electrical control circuit of the control mechanism of the present invention. Before describing the elements of the control circuits, it should be pointed out that variable speed motor M usually would in clude a potentiometer arranged in series with the motors actuating circuit as to cause variation in the motor's speed upon manual adjustment of the resistance of the potentiometer. In such an arrangement, the resistance value of the potentiometer directly controls the speed of the motor with the result that the speed of the motor, and the spindle driven thereby, varies as a linear function of the resistance change. Such an arrangement is unsatisfactory if the motor and spindle speed is to be varied as a nonlinear, hyperbolic function, which is necessary when a constant yarn speed is desired since the spindle speed must vary inversely with respect to the yarn package diameter. TI-le control circuit of FIG. 4 therefore provides a subcircuit 46 having a variable resistor 42, which is preferably a'potentiometer, in parallel with a fixed resistor 44. Due to the parallel arrangement of resistors 42, 44, the effective resistance across subcircuit 46 is an inverse function of the resistance of variable resistor 42. Linear variations in the resistance of resistor 42 therefore cause the speed of motor M and spindle as' sembly 20 to vary hyperbolically, when subcircuit 46 is connected to motor M. The control circuit also includes a second subcircuit 48 having a variable balance resistor 48 therein, and a transfer switch 50 for alternately connecting one or the other of subcircuits 46, 48 with motor M. When connected with motor M subcircuit 48 causes it to operate at a constant speed determined by the resistance of resistor 48. The arrangement permits the initial phase of a winding operation to be conducted at a constant spindle speed, assuming switch 50 then engages subcircuit 48, and the terminal phase to be conducted-upon movement of switch 50 to subcircuit 46-at a constant yarn speed. If the effective resistances of subcircuits 46, 48 are approximately equal when switch 50 is actuated, which equalization can be realized by an appropriate initial adjustment of the resistance of balance resistor 48', switching from one subcircuit to the other will not cause any significant variations in the speed of motor M and spindle assembly 46.

Referring now particularly to FIGS. 2 and 3, a mounting panel 52 provided within housing 30 of winder I has variable resistor 42, fixed resistor 44, and balance resistor 48' mounted thereon. The elongated wiper arm shaft 54 of resistor 42 extends through an opening in substantially U-shaped support panel 52 and is journaled between opposed walls thereof. A sleeve 58 is secured by any suitable means to the outer end of shaft 54. The inner end of drum 32 to which is secured a counterbalancing mechanism for maintaining constant pressure between package 22 and bail 26, the mechanism including a chain 38 and coil spring 40, is also disposed within housing 30. A lug 60 is secured to the periphery of drum 32 in a vertical plane (see FIG. 3) which includes sleeve 58. A drive cable 62 has one end attached to lug 60, its intermediate portion entrained about sleeve 58, and its other end attached to a framemounted tension spring 64. Rotation of drum 32 in a counterclockwise direction, as viewed in FIG. 3 and in response to increases in the diameter of yarn package 22, causes a resulting rotation of sleeve 58, and wiper arm shaft 54 of resistor 42, varying as previously discussed the resistance through subcircuit 46. Upon completion of a winding operation and return of 48 (FIG. 4) connected with motor M. Upon enga ement of flange 68 with lever SI, occasioned by movement 0 drum 32 and member 66 during a winding operation, switch 50 connects subcircuit 46 to motor M, simultaneously disconnecting subcircuit 48 therefrom. A full package knockoff switch 70 (FIGS. 2-4) also has its trip lever 72 in the path of movement of actuator member 66. As the winding operation and movement of drum 32 progress further, flange 68 of actuator 66 engages lever 72, opening switch 70 and stopping operation of motor M notwithstanding the then continued engagement of switch 50 by actuator 66.

Switches 50, 70 are respectively mounted upon plates 74, 76 carried by and adjustively pivotable about the axis of a sleeve-bolt 75 secured by a nut to wall 31 housing 30 in alignment with the axis of drum 32. Another bolt 77 extends through an arcuate slot 79 (FIG. 2) in plate 76 and is secured to wall 31 by nut 78. By loosening nuts 78, 80 and manipulat ing handle portions 82, 84 of plates 74, 76 respectively, switches 50, 70 may be pivoted to any desired positions in the path of pivotal movement of actuator 66. Transfer switching from constant spindle speed operation to constant yarn speed operation can therefore be made to transpire at any desired point in a winding cycle, as can automatic termination of the cycle. Transfer switching can also be prevented altogether if only constant spindle speed operation is desired, by pivoting switch 50 to an extreme position beyond the path of movement of actuator 66.

Although a specific embodiment of the invention has been shown and described, this was for purposes of illustration only, and not for purposes of limitation, the scope of the invention being in accordance with the follc wing claims.

We claim:

I. In a precision yarn winder including a frame, variable speed drive motor means carried by said frame, a driven yarn takeup spindle assembly upon which a yarn package of increasing diameter is adapted to be formed during progression of a winding operation, a yarn-traversing assembly carried by said frame and associated with said spindle assembly, a pivotable drum carried by said frame, and an elongate support arm connected at one end to said drum and at its other end supporting said spindle assembly for progressive movement away from said yarn-traversing assembly as the diameter of the yarn package increases during the winding operation, a spindle spaced control mechanism comprising:

a control circuit having a first subcircuit connectable with said drive means for varying speed operation of said spindle assembly and a second subcircuit connectable with said drive means for constant speed operation of said spindle assembly, transfer switch means actuable for connecting alternate ones of said subcircuits with said drive means, and full-package switch means actuable for stopping operation of said drive means;

and a switch actuating member carried by and pivotally movable with said drum, as the diameter of the yarn package increases during a winding operation, for actuating both of said switch means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 598 329 Dated August 10 1971 Inventor) Richard J. Savageau and Richard R. Pierce It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet At:torney-Donald H. Feldman" should read Agent-Donald H. Feldman Signed and sealed this l-th day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTISCHALK Attestlng Officer Acting Commissioner of Patents RM PO-1U (10-69? USCOMM-DC some-Pee u s anvilzuunnmum-um nrrlr: an hi 

1. In a precision yarn winder including a frame, variable speed drive motor means carried by said frame, a driven yarn takeup spindle assembly upon which a yarn package of increasing diameter is adapted to be formed during progression of a winding operation, a yarn-traversing assembly carried by said frame and associated with said spindle assembly, a pivotable drum carried by said frame, and an elongate support arm connected at one end to said drum and at its other end supporting said spindle assembly for progressive movement away from said yarn-traversing assembly as the diameter of the yarn package increases during the winding operation, a spindle spaced control mechanism comprising: a control circuit having a first subcircuit connectable with said drive means for varying speed operation of said spindle assembly and a second subcircuit connectable with said drive means for constant speed operation of said spindle assembly, transfer switch means actuable for connecting alternate ones of said subcircuits with said drive means, and full-package switch means actuable for stopping operation of said drive means; and a switch actuating member carried by and pivotally movable with said drum, as the diameter of the yarn package increases during a winding operation, for actuating both of said switch means. 